The basic types of wire strippers well known in the prior art are illustrated in U.S. Pat. Nos. 2,385,368, 2,695,537, 2,894,424 and 2,932,224. The latter two patents show tweezer or plier-like cutting tools having upper and lower cutting blades which are biased apart. In operation, the wire is placed between the blades and the tool is manually closed to cut into the insulation. By rotating the tool about the wire or cable, a relatively uniform gash may be made through the wire insulation.
The earlier two patents describe tubular devices through which the wire is inserted. Single point type blades extend into the inner part of the tubular device to engage the wire. The blade is biased away from the wire, but is mechanically forced by means of a screw thread into cutting relation with the wire at a predetermined depth.
All of these wire strippers are effective for use with wire and cable having a uniformly cylindrical outer shell, but will result in damage to the internal conductors if the contour of the outer shell is irregular. This is because, in each instance, the blade is substantially fixed with respect to the wire surface. Examining, in particular, the patent, Imman et al, U.S. Pat. No. 2,695,537, a device is shown having a blade that, once adjusted, will be fixed with respect to the wire surface. If the outer contour of the wire was undulating, as shown in FIG. 1, the blade would either miss the low portions or cut more deeply into the higher portions. Either way it is observed that undesirable operation occurs.
It is, therefore, an object of this invention to provide a stripping tool which will be effective to uniformly slice a cable having an irregular outer surface.